A node to which bidirectional message channels are connected for transmitting and receiving is considered in a communication network. Traffic sources and traffic sinks are connected to the other end of these message channels. The transmission power of the traffic sources is unknown, and the traffic sources are not all always active. A number of message channels may be connected to one node. A protocol which has a window mechanism for controlling the number of messages which a traffic source may send without acknowledgement is used for reliable message transmission.
A reception overload can occur in a node such as this if the messages arriving on the message channels exceed the capacity of the receiving device for that node. In this case, messages are rejected.
One problem is to find a suitable method for flow control which protects the node against being overloaded. This flow control must reliably cope with the following problem elements:                a small number of message channels have a high volume of traffic, which results in an overload situation;        a large number of message channels have a small amount of message traffic, producing an overload situation overall; and        no computation power should be consumed for flow control when a message channel is inactive, and little computation power should be consumed when a message channel has a small amount of message traffic;        
One known solution to this problem is to define connection guidelines which restrict the number of message channels which can be connected to one node. This leads to a large amount of capacity being reserved in order to deal with overload situations which occur rarely.
A further known method solves the problem in two steps. In a first step, the window size is reduced to an estimated load which can be coped with, and fine adjustment is carried out in a second step, as a function of the overload indication. This can be used sensibly only for a small number of message channels with a known transmission power whose level is constantly high; in particular, this solution is not able to deal with inactive message channels without using computation power.
An object to which the present invention is directed, is to avoid the disadvantages of the previously known methods for flow control for a number of transmitters with an unknown and/or different transmission power.